Gin Admin theme - submit button issue

Ah I just realized I am using Cancel → button module. Once I disable it - it works as expected. So it is caused by this module. However once I disable ECA model it also works, so looks like ECA and Entity Form Cancel Button are not compatible in this case.

So not sure if anyone can help - and determine why ECA Entity Form Build Entity task has such "weird" impact.

It's actually not only the cancel button module and ECA, there is also Gin in the game which does a lot of magic to expose action buttons in the top-right corner of the sticky area. And even that will soon change a lot, as in Drupal core there will be the new navigation module and the toolbar module being removed. By then, Gin will no longer have to handle the sticky action buttons, and that'll change this whole behaviour too.

That said, I'm not sure if it's worth trying to figure out which component would have to be adjusted, could be all 3, actually.